To be in for the full season you have to post your team by the start of Fp1 on Friday ,,,check your local timezones when that is.

Don't worry if you miss it, or even want to take a tactical look at the runners before joining, you can enter at any time with your entry being included in the next event.
The start of FP1 is always the cut off for each event

Anyone wanting to take a punt at creating a team with whatever hindsight you are able to apply after Melbourne, the cut off is the start of FP1 in the early hours of Friday UK time...check the time locally to you.